Prepare a project for release from SCM. This checks all
changes are committed, and prompts for a tag and version
name to release the project with. It will update project.xml locally
and in the SCM system, as well as tagging the SCM as requested.

scm:perform-release

This task checks out the project from SCM at any location, from the
tag requested. It then builds a clean version of the code and deploys
it to the remote repository.
You can automate this using the appropriate properties, but for any
that are not provided you will be prompted for them.

scm:create-patch

Creates a patch in ${maven.scm.patch.dir}/${maven.scm.patch.file}
of the changes made to the current project